Padlock with lockable shackle

ABSTRACT

The invention relates to a padlock ( 1 ) which is provided with a shackle ( 2 ). The padlock has a flat housing ( 3 ) in which retaining means ( 9, 10 ) are arranged. Retaining elements ( 7, 8 ) are positioned at the free end of the shackle ( 2 ″). The retaining means ( 9, 10 ) are located at a retaining plate ( 4 ) which is arranged in the interior of the flat housing ( 3 ). Preferably, the housing ( 3 ), shackle ( 2 ) and retaining plate ( 4 ) are manufactured in a single piece, i.e., they are firmly linked to each other. One of the advantages of the invention is that, once the shackle is locked, it cannot be opened except by breaking or deforming it so that tampering can be easily detected.

BACKGROUND AND SUMMARY OF THE INVENTION

The present invention relates to a padlock with lockable shackle inaccordance with the preamble of claim 1.

A plurality of such padlocks exist, because they are also known aspadlocks (English). In particular, with such padlocks, wherein, once theshackle is locked, the padlock can no longer be opened withoutdestroying it, there is the problem, on the one hand, of preventing asmuch as possible attempts to tamper with the lock and, on the otherhand, of rendering said tampering visible and detectable.

Thus, for example, the U.S. Pat. No. 4,779,911 discloses such a padlock,which is constructed of few parts. Once the shackle has been locked, itcannot be opened without breaking it. In this respect the two ends of aU-shaped shackle, made of metal, are disposed in a box-shaped housing.In the unused, open state only one end of the shackle can be slidlongitudinally between two stops and swung sideways in this housing.Thus, the shackle can be used as prescribed, for example, by insertingthe free end into one eye or several eyes. Finally the free end can beinserted into the corresponding opening in the padlock housing, wherethere are springy retaining means, which are inaccessible from theoutside and which at this stage hold these ends of the U-shaped shackleimmoveably. Thus, the springy retaining means engage with an annulargroove, designed on the end of the shackle. Now the padlock must beopened by serving the U-shaped shackle with a tool, thus rendering thepadlock useless for reuse.

This prior art embodiment of a padlock is, indeed, simply constructedfrom only a few parts, but is exhibits some shortcomings, especiallywith respect to protection against tampering.

The object of the present invention comprised at this stage of providingsuch a padlock, which is believed to be even simpler in its constructionand at the same time is believed to provide better protection againsttampering.

The invention solves this problem with a padlock with the featuresdisclosed in claim 1.

One advantage of such an inventive padlock is that it can bemanufactured preferably in one piece and is very well protected againsttampering owing to the fact that the locking members are not accessiblefrom the outside and are not open in the interior of the housing. Sincethe padlock is manufactured in one piece, it still exhibits, despite itsprotection against tampering, the advantages of a simple construction.As an inexpensive mass produced article, such a padlock is especiallysuitable for application in areas requiring good protection or goodprotection against tampering.

Preferred designs of the invention follow from the dependent claims 2 to9.

One embodiment of the present invention is explained in detail belowwith reference to the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top view of a detail of the inventive padlock in the closedposition;

FIG. 2 is a longitudinal view of the padlock in FIG. 1; and

FIG. 3 is a view of the padlock blank in accordance with FIG. 1.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view of a detail of the inventive padlock 1 in the closedposition, that is, with closed shackle 2. The padlock 1 exhibits a flat,shell-shaped housing 3, which exhibits at the top and on its front sideclosed walls 3′ and 3″. The interior of the housing 3 exhibits aretaining plate 4, which forms simultaneously the bottom and rear sidewalls 4′ and 4″ of the padlock 1. This retaining plate 4 is connected,on the one hand, to the housing 3 by way of the bridge 5 and isconnected, on the other hand, in the bottom corner to the side walls ofthe housing 3 by way of mortising 6 or a rivet. Thus, the retainingplate 4 lies immoveably in the interior of the housing 3 and cannot bedetached from it without visible tampering.

The shackle 2 is also connected with its one end 2′ to the housing 3,preferably in one piece. The free end 2″ of the shackle is designed as aretaining member and terminates in the closed position in the matchingretaining means of the retaining plate 4.

Preferably a retaining tooth 7 and a similarly tooth-shaped stop cam 8serve as the retaining members of the shackle 2. Said retaining toothand stop cam act against each other. These retaining members 7, 8 engagewith the matching retaining means of the retaining plate 4; thus, inthis case preferably with a flexible tongue 9 with a rocking baby 10,which is also designed so as to be flexible. In the closed position ofthe padlock 1, depicted in FIG. 1, the shackle end 2″ is held immoveablyin the housing 3 by way of the rocking baby 10, that is by way of itstwo beveled end regions, which are moved against the retaining tooth 7and the stop cam 8. Thus, the shackle end cannot be removed withoutbreaking it.

This feature is supported by, among other things, the thickening 11,which is formed preferably on the shackle 2 in the transition to theshackle end 2″. The thickening 11, for example in the form of a ring, isdesigned in such a manner that it closes the insert opening 12 for theshackle end 2″ in the top side 3′ of the housing 3 in the closed stateand thus prevents a tool from being inserted into the gap formed by thisopening 12 and the shackle end 2″ for the purpose of tampering with theconnection of the retaining members 7, 8 or the retaining means 9, 10.This process is also impeded by the preferably curved design of theshackle end 2″, which prevents the insertion of a straight tamperingtool.

If an attempt is supposed to be made to server the shackle 2 from thehousing 3 with force, the shackle 2 is broken, first of all, at thepreferably predetermined breaking point 13, thus rendering the tamperingattempt detectable. Since this predetermined breaking point 13 liesabove the thickening 11, the shackle end 2″ remains in this case in thehousing 3 of the padlock 1 and cannot be removed even with the use of atool without also damaging the housing 3.

Even if this stage a tool could be inserted into the said gap, theresult of the design of the retaining means in the form of a rocker 10is that it will not be possible to displace to such an extentsimultaneously both the bottom region of the rocker 10, which makescontact with the retaining tooth 7, and also the top part of the rocker10, which makes contact with the stop cam 8, that the shackle end 2″could be removed from the opening 12 without visibly damaging thehousing 3.

Furthermore, the shackle end 2′ exhibits preferably a flat cone 15,which projects in the direction of the shackle opening and which in theclosed state of the padlock 1 rests against cheeks 14, formed on bothside surfaces of the housing 3, and is thus guided sideways from saidcheeks. Thus, it is prevented that the shackle end 2′ in the transitionarea to the housing 3 is exposed to lateral stress, which could resistin the shackle 2 breaking in this area. Of course, the cone 15 couldalso be formed on the housing 3 itself and said cone could act betweentwo parallel cheeks 15, disposed on the shackle end 2′.

An especially significant advantage of the present padlock 1 lies now inthe fact that it is constructed in such a manner that is can be producedin one piece, as follows from the view in FIG. 3. The threeparts—housing 3, retaining plate 4 and shackle 2—can be manufactured asa single injection molded part. The areas are connected together by wayof the bridge 5 and the shackle end 2′. Thus, the retaining plate 4 canbe swivelled simply around the bridge 5 into the cavity of the housing 3and connected immoveably to an open padlock 1 preferably by way ofmortising 6.

Provided in this manner, is thus a one-piece padlock 1, also calledpadlock (English), which, in contrast to many such prior art one-piecepadlocks, is protected especially against tampering, as presented above,owing to the completely closed locking area.

What is claimed is:
 1. Padlock with a shackle, which projects from aface of a flat housing, a free end of the shackle exhibiting a retainingmember, which in a closed position engages with a springy retainer in aninterior of the housing and thereby closes a shackle opening through theface of the housing, wherein the housing is designed in a shape of ashell and the retainer is formed on a retaining plate, which ispositioned in the interior of the housing, so that the retaining plateforms simultaneously at least a bottom wall of the housing which liesopposite the face, and wherein the retaining member is designed as acurved arm with at least two counter-acting toothed recesses on oneside.
 2. Padlock according to claim 1, wherein the shackle exhibits athickening in a transition area to the retaining member.
 3. Padlockaccording to claim 2, wherein the padlock is one single piece. 4.Padlock according to claim 1, wherein the retaining plate is connectedby way of mortising to the housing.
 5. Padlock according to claim 4,wherein the mortising is on a side of the housing opposite from theshackle.
 6. Padlock according to claim 4, wherein the padlock is made ofplastic.
 7. Padlock according to claim 1, wherein when closed a shackleend that is connected to the housing is guided by way of mortisingbetween cheeks formed on the housing.
 8. Padlock according to claim 1,wherein the padlock is made of plastic.
 9. Padlock according to claim 1,wherein the padlock is one single piece.
 10. Padlock with a shackle,which projects from a face of a flat housing, a free end of the shackleexhibiting a retaining member, which in a closed position engages with aspringy retainer in an interior of the housing and thereby close ashackle opening through the face of the housing, wherein the housing isdesigned in a shape of a shell and the retainer is formed on a retainingplate, which is positioned in the interior of the housing, so that theretaining plate forms simultaneously at least a bottom wall of thehousing which lies opposite the face, wherein the retaining platesubstantially entirely fills the interior of the housing, and whereinthe retaining member is designed as a curved arm with at least twocounter-acting toothed recesses on one side.
 11. Padlock according toclaim 10, wherein above an area with the retaining member the shackleexhibits a predetermined breaking point.
 12. Padlock according to claim11, wherein the breaking point is a rhombic or square recess in theshackle.
 13. Padlock according to claim 12, wherein the padlock is onesingle piece.
 14. Padlock according to claim 11, wherein the padlock ismade of plastic.